diff --git a/backend/llm.py b/backend/llm.py
index a0f49e4..e4250d3 100644
--- a/backend/llm.py
+++ b/backend/llm.py
@@ -36,7 +36,12 @@ async def stream_openai_response(
     model = Llm.GPT_4_VISION
 
     # Base parameters
-    params = {"model": model, "messages": messages, "stream": True, "timeout": 600}
+    params = {
+        "model": model.value,
+        "messages": messages,
+        "stream": True,
+        "timeout": 600,
+    }
 
     # Add 'max_tokens' only if the model is a GPT4 vision model
     if model == Llm.GPT_4_VISION: